Whatever the reason for the war, the situation looked grim for the Danes - who nevertheless fought well. Despite intermittent efforts to resolve the conflict through negotiation (including a peace conference in London), the war continued until the Danes were forced to admit defeat. The war ended with Denmarkceding the three duchies to the victors - essentially, to Prussia.

The new border remained in effect until 1920, when (as part of the settlements after WWI) Denmark regained the northern part of the Duchy of Schleswig.